A semiconductor heterostructure can be modeled by a system of equations describing (with a certain degree of completeness and precision) the state of the system. The equations depend on a set of structural and compositional data: the spatial dependence of the chemical composition (including dopant profiles), the applied external fields, etc. The system behavior (response) is described by functi...

Inverse sampling design is generally considered to be appropriate technique when the population is divided into two subpopulations, one of which contains only few units. In this paper, we derive the Horvitz-Thompson estimator for the population mean under inverse sampling designs, where subpopulation sizes are known. We then introduce an alternative unbiased estimator, corresponding to post-st...

Despite the voluminous publications on robot dynamics and control, the literature to date is based solely on the serial link manipulators. Little attention has been given to the alternative manipulator design based on the concept of in-parallel actuated mechanism, which is characterized by its excellent rigidity, high strength-to-moving-weight ratio, and relatively simple inverse kinematics. Th...

This paper presents design and kinematic analysis for a cable-driven parallel robotic (CDPR) manipulator with four cables, The CDPR manipulator produces a planar motion including two translational and one rotational degrees of freedom. To move the end-effector of CDPR, its kinematic structure is analyzed and the inverse kinematics is formulated in the closed-form solution. The experimental test...

Gaits are crucial to the performance of locomotors. However, it is often difficult to design effective gaits for complex locomotors. Geometric mechanics offers powerful gait design tools, but the utilities of these tools have been limited to systems with two joints. Using shape basis functions, it is possible to approximate the kinematics of complex locomotors using only two shape variables. As...

This paper describes the control system design concepts for the Mars Volatiles and Climate Surveyor (MVACS) Robotic Arm which supports the scientiic investigations to be conducted as part of the Mars Surveyor '98 Lander project. Solutions are presented to some of the problems encountered in this demanding space application with its tight constraints on mass, power, volume, and computing resourc...

This paper describes an approach for automatic robot motion planning. A starting path consisting of the direct line connection from start to goal in the configuration space is generated first. At the most colliding configuration a new point is added and moved out of the collision. For this the configuration space is approximated using a corresponding skeleton robot and a point-like obstacle. A ...

The aim of this study was to investigate the effect of errors in the location of the center of pressure (5 and 10 mm) on joint moment uncertainties at different gait velocities (1.0, 1.5, and 2.0 m/s). Joint moments of five healthy young adults were calculated by inverse dynamics using the bottom-up approach. Results indicated that there is a linear relationship between errors in center of pres...

A computational framework for analyzing and designing efficient flapping flight vehicles is presented. Two computational tools are considered: a Betz Criterion code proposed by Hall et. al., and an accelerated, unsteady, potential flow solver. The parameters considered in this paper are: the flapping frequency, the flapping amplitude in both up-down and forward-aft directions, and the addition ...